Chris Pratt visited a children's cancer centre dressed as Star-Lord today (06.02.15) after losing a Super Bowl bet to Chris Evans.

Chris Pratt

Chris Pratt

The 'Guardians of the Galaxy' star, who is a diehard Seattle Seahawks fan, surprised young patients at Christopher's Haven treatment facility in Boston in a half-human, half-alien costume alongside his close pal after his team lost the American football game to Evan's team, The New England Patriots, last Sunday (01.02.15).

The duo's Twitterbowl 2015 fundraising challenge helped raise $12,000 for the hospital and $15,000 for Seattle Children's Hospital and they agreed that the loser would have to visit the winner's local facility.

The 35-year-old actor, who is married to Anna Faris, shared a number of photographs from the special visit on Facebook, with the caption: "Made good on that ‪#‎twitterbowl‬ bet! Starlord is roud to be in Boston today at #ChristophersHChristopher's Haven with Chris Evans and some awesome families. ‪#‎12thMan‬ (sic)"

The 'Parks and Recreation' star also arrived at the treatment facility in a New England Patriots jersey in a further bid to amuse the children and their families.

Evans previously praised his friend for agreeing to go through with the bet on Twitter, writing: "Thank you to @prattprattpratt for being a good sport. I'll be there with you at @chris_haven, and don't worry @seattlechildren, we'll be coming there too!"